RESUMEN
The redox stabilities of different oxygen donor solvents (CâO, PâO and SâO) and lithium salt anions for supercapacitors (SCs) electrolytes have been compared by calculating the frontier molecular orbital energy. Among six lithium difluoro(oxalate)borate (LiDFOB)-based mono-solvent electrolytes, the dilute LiDFOB-1,4-butyrolactone (GBL) electrolyte exhibits the highest operating voltage but suffers from electrolyte breakdown at elevated temperatures. Trimethyl phosphate (TMP) exhibits the highest redox stability and a strongly negative electrostatic potential (ESP), making it suitable for promoting the dissolution of LiDFOB as expected. Therefore, TMP is selected as a co-solvent into LiDFOB-GBL electrolyte to regulate Li+ solvation structure and improve the operability of electrolytes at high temperatures. The electrochemical stable potential window (ESPW) of 0.5 m LiDFOB-G/T(5/5) hybrid electrolyte can reach 5.230 V. The activated carbon (AC)-based symmetric SC using 0.5 m LiDFOB-G/T(5/5) hybrid electrolyte achieves a high energy density of 54.2 Wh kg-1 at 1.35 kW kg-1 and the capacitance retention reaches 89.2% after 10 000 cycles. The operating voltage of SC can be maintained above 2 V when the temperature rises to 60 °C.
RESUMEN
A new compound, ethyl 5-phenyl-2-(p-tolyl)-2H-1,2,3-triazole-4-carboxylate was successfully introduced and synthesized as a novel rhodamine B derivative named REPPC, and characterized by 1 H nuclear magnetic resonance (NMR), 13 C NMR, and high resolution mass spectrometry (HRMS). It showed an obvious fluorescence and UV-visible light absorption enhancement towards Hg2+ ion without interference from common metal ions in N,N-dimethylformamide-H2 O (pH 7.4). The spirolactam ring moiety of rhodamine in REPPC was converted to the open-ring form generating a 1:1 complex with the intervention of a mercury ion, verified by electrospray ionization-mass spectroscopy testing and density functional theory calculation. REPPC was used to visualize the level of mercury ions in living HeLa cells with encouraging results.